package cn.datastruct.four;

public abstract class Stack  {

    //判断是否为空
    public abstract boolean isEmpty();

    //判断是否满了
    public abstract boolean isFull();

    //push(),添加元素
    public abstract void push();

    //pop(),出栈
    public abstract void pop();

    //求栈长度
    public abstract int length();

    //打印栈
    public abstract void showStack();
}
